The Collaborative International Dictionary of English v.0.48:

Friendless \Friend"less\, a. [AS. fre['o]ndle['a]s.]
   Destitute of friends; forsaken. -- Friend"less*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

friendless
    adj 1: excluded from a society [syn: friendless, outcast]

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "friendless":
   abandoned, aidless, alienated, alone, aloof, apart, companionless,
   defenseless, deserted, desolate, detached, fatherless, forlorn,
   forsaken, godforsaken, guideless, helpless, homeless, insular,
   isolated, kithless, leaderless, lone, lonely, lonesome, motherless,
   outcast, pregnable, removed, rootless, separate, separated,
   single-handed, solitary, solo, unabetted, unaccompanied, unaided,
   unassisted, unattended, unescorted, unfriended, unprotected,
   unseconded, unsupported, untenable, vulnerable, withdrawn



The Devil's Dictionary (1881-1906):

FRIENDLESS, adj.  Having no favors to bestow.  Destitute of fortune.
Addicted to utterance of truth and common sense.